HR: 1340h
AN: U43A-0744    [Abstracts]
TI: North American Terrestrial Climate Connection to Solar, Ocean, and Ice Core Records on Millennial-Scales During the Holocene
AU: * Viau, A E
EM: aviau@uottawa.ca
AF: Laboratory for Paleoclimatology and Climatology, Department of Geography,60 University St.,University of Ottawa, Ottawa, ON K1N 6N5 Canada
AU: Gajewski, K
EM: gajewski@uottawa.ca
AF: Laboratory for Paleoclimatology and Climatology, Department of Geography,60 University St.,University of Ottawa, Ottawa, ON K1N 6N5 Canada
AU: Sawada, M C
EM: msawada@uottawa.ca
AF: Laboratory for Paleoclimatology and Climatology, Department of Geography,60 University St.,University of Ottawa, Ottawa, ON K1N 6N5 Canada
AB: A leading hypothesis for millennial-scale climate variability during the Holocene is solar output variations. However, the timing and expression of this variability in individual high-resolution records has proven ambiguous. We discuss a continental-scale North American pollen-based temperature reconstruction that correlates in the frequency domain with marine records from the North Atlantic (IRD, NADW) and cosmogenic nuclide records, proxies for solar output variations (14C, 10Be) as well as other records from around the world. Because our temperature reconstruction is based on hundreds of sites and thousands of dates, the climate signal is more readily identified then from reconstructions based on one site, which are affected by local non-climatic factors. The incorporation of time and space results in a higher probability of extracting the climate signal than in any individual high-resolution record. Coherency in the frequency domain between our temperature time series and other marine, terrestrial and ice records suggests that the climate as a whole varied at a more periodic 1,000 ñ 100 years during the Holocene. Indeed, uncovering a common frequency between the different climate records of the Holocene is key to disentangling climate variability on millennial-scales. It appears likely that Holocene climate variations on millennial-scale resulted from an external cause, potentially solar output variations, associated with internal feedbacks acting as amplifiers.
DE: 3344 Paleoclimatology
DE: 1600 GLOBAL CHANGE (New category)
DE: 1620 Climate dynamics (3309)
DE: 1650 Solar variability
SC: Union [U]
MN: 2004 AGU Fall Meeting